Telephone relay or step-up.



No. 743,589. PATENTED NOV. 10, 1903. G. B. SUNDQUISI'.

v TELEPHONE RELAY OR STEP-UP.

APPLICATION FILED MAY 14., 1902.

N0 MODEL.

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UNITED STATES GUSTAVUS Patented November 10, 1903.

E. SUNDQUIST, OF CLEVELAND, OHIO, ASSIGNOR OF ONE-HALF TO ALBERT H. WAHL, OF CLEVELAND, OHIO.

TELEPHONE RELAY OR STEP-UP.

SPECIFICATION forming part of Letters Patent No. 743,589, dated November 10, 1903. Application filed llllay 14:, 1902. $eria] Ho. 107,281. (No model) To all whmn it may concern:

Be it known that I, GUSTAVUS E. SUND- QU 151, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and 5 State of Ohio, have invented certain new and useful Improvements in Telephone Relays or Step-Ups; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being bad to the accompanying drawings, and to the letters and figures of reference marked thereon,

' which form a part of this specification.

I Myinvention relates to telephone relays or step-ups, and has for its object to provide improved means whereby sound undulations conveyed by one line or line-section may be transmitted to another line or line-section with increased volume and to so arrange said means that the lines may be worked from either direction.

For a clear understanding of my invention I have in the accompanying drawings illustrated diagrammatically the embodiment thereof in suitable mechanical devices.

Figure 1 represents a preferred embodiment thereof employing a triple-wound inductioncoil of peculiar arrangement and a single pri- 3o mary battery, and Fig. 2 represents a somewhat modified arrangement employing two ordinary ind notion-coils and two primary batteries.

In the drawings, A and B represent, respectively, two separated lines or line-sections,

which may consist of closed metallic circuits,

grounded circuits, or one metallic and one grounded circuit.

In the form of my invention shown in Fig. 1, l and l are receivers or hand-phones, pref erably of the bipolar type, arranged, respectively, in the line-circuits A and B.

2 and 2 are secondaries of an inductioncoil, (indicated as a whole by 3,) said second- 5 aries being likewise included, respectively, in

the circuits A and B.

4 and 4 indicate microphone-transmitters opposed, respectively, to the receivers or handphones 1 and 1 and both arranged in a common primary circuit C, including therein a battery 5 and the primary 6 of the inductioncoil 3. The inductioncoil is thus triplewound with two secondaries and one primary. By this arrangement the electrical impulses received by one secondary are transmitted to the other. 7

Thetransinitters 4 and 4 are preferably of the granular-carbon type and are preferably screwed or otherwise secured directly to the face of their respective receivers, so that the vibrations of the receiver-diaphragm are communicated directly thereto.

The circuit through the relay may be traced as follows: Assuming that the message is received from line A for transmission over line B, the sound-producing undulations enter on line-circuit A, pass through the receiver 1 and the secondary 2 and thence return by the metallic circuit or to ground. The secondary Z influences the secondary 2 induc- 7o ing talking-currents therein of equal strength with those received, while the receiver 1 transmits the vibrations occasioned therein directly to the microphone 4:, causing corresponding undulations in the primary circuit,

including the primary coil and the primary battery. The current thus produced in the primary circuit induces in the secondary coil 2 talking-currents of the desired intensity, which are transmitted over the line B, as will be readily understood.

The symmetrical arrangement of parts permits the relay to operate from either side, so when voice-currents are sent over the line B they pass through receiver 1 and the secondary 2 and thence to return, and the secondary 2 induces currents in the secondary 2 While the receiver 1 transmits vibrations to the microphone 4 causing corresponding undulations in the primary of the induction-coil.

What I claim, and desire to secure by Letters Patent, is

1. A telephone relay embodying in combination two lines or line-sections, each having in its circuit a receiver and a secondary of an ing in series circuit therein a coil arranged for inductive efiect and a telephone-receiver, of a single closed local circuit including therein a coil arranged in inductive relation to both of the line-coils, a primary source of electric supply, and tWo microphones operatively associated with the two line-receivers.

In testimony whereof I affix my signature in 20 presence of tWo Witnesses.

GUSTAVUS E. SUNDQUIST.

Witnesses:

ALBERT H. WAHL, J OHN A. BOMMHARDT. 

